A polyamide was prepared by condensation of
trans-2, 5-dimethyl piperazine and terephthaloyl chloride in chloroform solution using triethylamine at 2°C. The number average molecular weight
Mn of the polyamide was 1.7×10
4. Formic acid and formic acid-chloroform mixture were used as casting solvents. The ultrafiltration performance of the membrane prepared from a HCOOH-CHCl
3 solution was more dependent upon gelation medium than upon polymer content in casting solution, solvent composition or evaporation period. The membrane with a water flux of 18
l/m
2hr (4kg/cm
2 at 20°C) was formed from a HCOOH-CHCl
3 solution and its structure was observed by a scanning electron microscope. The membrane had an anisotropic structure constructed with both a thin active layer of 0.9-1.2μm and a porous support layer of 40μm. The membrane formed from mixed solvent exhibited a high rejection for Cytochrome C, while the one from formic acid as solvent showed a little rejection. The membrane having a water flux of 5.8
l/m
2hr exhibited rejections of 99.4% for Cytochrome C and of 72.7% for Vitamin B
12. At 166
l/m
2hr water flux level, the rejections for Hemoglobin, Cytochrome C, and Vitamin B
12 were 95.6, 79.4, and 38.8%, respectively.
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